Research Abstracts Online
January 2009 - March 2010

University of Minnesota Twin Cities
Institute of Technology
Department of Mechanical Engineering

PI: Thomas H. Kuehn, Fellow

Simulation of Virus Aerosol Processes

In most virus aerosol studies, aerosolization efficiency—the ratio of viable virus collected by bioaerosol samplers to the quantity of viable virus generated by nebulizers—is generally very low, e.g. less than 10%. Research has shown that an aerosolization efficiency much lower than 100% could be caused by loss of virus during transport through the air stream, inactivation of virus due to environmental or sampling stress, and low physical collection efficiency of samplers. However, the aerosol generation process may also contribute to the low aerosolization efficiency. For example, the extremely high hydrodynamic shear rate (~106 s-1) during jet nebulization may be responsible for the inactivation of virus. This project uses commercial CFD software packages to simulate the virus aerosol generation process. By introducing particles (as single virions) into liquid to simulate a virus suspension, a time history of the shear rate and shear stress experienced by virus during the nebulization process can be obtained. With known information of virus viability before and after nebulization from experiment, the effect of aerosol generation process on virus viability and thus aerosolization efficiency can then be quantified by the shear rate and shear stress during nebulization. FLUENT will also be used to model and simulate our ventilation chamber to study the airflow patterns and particle movements under different boundary conditions. The researchers use this chamber to perform experiments that simulate field sampling for virus aerosols. The simulations will assist in the design of the experiments and may provide additional information on the nature of the virus aerosol dispersion.